(CNN) -- Security forces opened fire Tuesday on an afternoon funeral procession for people slain in the restive city of Homs the day before, according to an activist and an activist group.

The Local Coordination Committees of Syria said that at least 10 people died and many were wounded. In a second account, an activist in Homs told CNN said at least seven people were killed and more than 50 others were wounded when security and army forces shot at the mourners.

The activist -- who said the incident happened at the Kahlid ben Al-Waleed cemetery, where the funeral procession were taking place -- said security and army forces opened fire.

A heavy security presence permeated the western Syrian city as snipers took positions on building rooftops and people couldn't leave their homes in some neighborhoods where large protests have occurred.

Videos emerging out of what is purportedly Homs showed hectic scenes.

In one, people carried a stretcher with a body on it and ran toward a pickup truck amid sounds of gunfire. The shooter of the footage said that security forces are firing at people in the procession.

In the other, there is heavy gunfire and people hiding behind walls. Someone says security forces are shooting at protesters and people attending the funeral procession.

There was no immediate government response and CNN could not independently verify the information.

Homs residents reported heavy bursts of gunfire, helicopters, and house raids over the last 24 hours. The government blamed the latest round of violence on armed terrorist groups.

This unrest in Syria began in mid-March after teens were arrested for writing anti-government graffiti in the southern city of Daraa, according to Amnesty International.

As the clashes intensified, demonstrators changed their demands from calls for freedom and an end to abuses by the security forces to calls for the regime's overthrow.

On April 19, Syria's Cabinet lifted an emergency law that had been in effect since 1963. But security forces then moved quickly to crack down. Government opponents have alleged massive human rights abuses.